scholarly journals NGS and phenotypic ontology-based approaches increase the diagnostic yield in syndromic retinal diseases

2021 ◽  
Author(s):  
I. Perea-Romero ◽  
F. Blanco-Kelly ◽  
I. Sanchez-Navarro ◽  
I. Lorda-Sanchez ◽  
S. Tahsin-Swafiri ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Diagnostic Yield ◽  
A Priori ◽  
Retinal Diseases ◽  
Human Phenotype ◽  
Whole Exome ◽  
Next Generation Sequencing Ngs ◽  
Generation Sequencing ◽  
Clinical Category ◽  
Selection Of

AbstractSyndromic retinal diseases (SRDs) are a group of complex inherited systemic disorders, with challenging molecular underpinnings and clinical management. Our main goal is to improve clinical and molecular SRDs diagnosis, by applying a structured phenotypic ontology and next-generation sequencing (NGS)-based pipelines. A prospective and retrospective cohort study was performed on 100 probands with an a priori diagnosis of non-Usher SRDs, using available clinical data, including Human Phenotype Ontology annotation, and further classification into seven clinical categories (ciliopathies, specific syndromes and five others). Retrospective molecular diagnosis was assessed using different molecular and bioinformatic methods depending on availability. Subsequently, uncharacterized probands were prospectively screened using other NGS approaches to extend the number of analyzed genes. After phenotypic classification, ciliopathies were the most common SRD (35%). A global characterization rate of 52% was obtained, with six cases incompletely characterized for a gene that partially explained the phenotype. An improved characterization rate was achieved addressing prospective cases (83%) and well-recognizable syndrome (62%) subgroups. The 27% of the fully characterized cases were reclassified into a different clinical category after identification of the disease-causing gene. Clinical-exome sequencing is the most appropriate first-tier approach for prospective cases, whereas whole-exome sequencing and bioinformatic reanalysis increases the diagnosis of uncharacterized retrospective cases to 45%, mostly those with unspecific symptoms. Our study describes a comprehensive approach to SRDs in daily clinical practice and the importance of thorough clinical assessment and selection of the most appropriate molecular test to be used to solve these complex cases and elucidate novel associations.

scholarly journals Whole-exome sequencing and its impact in hereditary hearing loss

2015 ◽  
Vol 97 ◽  
Author(s):  
TAHIR ATIK ◽  
GUNEY BADEMCI ◽  
OSCAR DIAZ-HORTA ◽  
SUSAN H. BLANTON ◽  
MUSTAFA TEKIN
Keyword(s):  
Hearing Loss ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Hereditary Deafness ◽  
Whole Exome ◽  
Human Genes ◽  
Genetic Revolution ◽  
Recent Developments ◽  
Next Generation Sequencing Ngs ◽  
Generation Sequencing

SummaryNext-generation sequencing (NGS) technologies have played a central role in the genetic revolution. These technologies, especially whole-exome sequencing, have become the primary tool of geneticists to identify the causative DNA variants in Mendelian disorders, including hereditary deafness. Current research estimates that 1% of all human genes have a function in hearing. To date, mutations in over 80 genes have been reported to cause nonsyndromic hearing loss (NSHL). Strikingly, more than a quarter of all known genes related to NSHL were discovered in the past 5 years via NGS technologies. In this article, we review recent developments in the usage of NGS for hereditary deafness, with an emphasis on whole-exome sequencing.

scholarly journals Progressive Myoclonus Epilepsies

2021 ◽  
Vol 7 (6) ◽  
pp. e641
Author(s):  
Laura Canafoglia ◽  
Silvana Franceschetti ◽  
Antonio Gambardella ◽  
Pasquale Striano ◽  
Anna Teresa Giallonardo ◽  
...  
Keyword(s):  
Late Onset ◽  
Diagnostic Yield ◽  
Homozygosity Mapping ◽  
Genetic Origin ◽  
Pathogenic Variants ◽  
Whole Exome ◽  
Progressive Ataxia ◽  
Targeted Ngs ◽  
Next Generation Sequencing Ngs ◽  
Generation Sequencing

Background and ObjectivesTo assess the current diagnostic yield of genetic testing for the progressive myoclonus epilepsies (PMEs) of an Italian series described in 2014 where Unverricht-Lundborg and Lafora diseases accounted for ∼50% of the cohort.MethodsOf 47/165 unrelated patients with PME of indeterminate genetic origin, 38 underwent new molecular evaluations. Various next-generation sequencing (NGS) techniques were applied including gene panel analysis (n = 7) and/or whole-exome sequencing (WES) (WES singleton n = 29, WES trio n = 7, and WES sibling n = 4). In 1 family, homozygosity mapping was followed by targeted NGS. Clinically, the patients were grouped in 4 phenotypic categories: “Unverricht-Lundborg disease-like PME,” “late-onset PME,” “PME plus developmental delay,” and “PME plus dementia.”ResultsSixteen of 38 (42%) unrelated patients reached a positive diagnosis, increasing the overall proportion of solved families in the total series from 72% to 82%. Likely pathogenic variants were identified in NEU1 (2 families), CERS1 (1 family), and in 13 nonfamilial patients in KCNC1 (3), DHDDS (3), SACS, CACNA2D2, STUB1, AFG3L2, CLN6, NAXE, and CHD2. Across the different phenotypic categories, the diagnostic rate was similar, and the same gene could be found in different phenotypic categories.DiscussionThe application of NGS technology to unsolved patients with PME has revealed a collection of very rare genetic causes. Pathogenic variants were detected in both established PME genes and in genes not previously associated with PME, but with progressive ataxia or with developmental encephalopathies. With a diagnostic yield >80%, PME is one of the best genetically defined epilepsy syndromes.

scholarly journals Next-Generation Sequencing in the Field of Primary Immunodeficiencies: Current Yield, Challenges, and Future Perspectives

2021 ◽  
Author(s):  
Emil E. Vorsteveld ◽  
Alexander Hoischen ◽  
Caspar I. van der Made
Keyword(s):  
Next Generation Sequencing ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Diagnostic Yield ◽  
Primary Immunodeficiencies ◽  
Next Generation ◽  
Inborn Errors ◽  
New Genes ◽  
Whole Exome ◽  
Generation Sequencing

AbstractPrimary immunodeficiencies comprise a group of inborn errors of immunity that display significant clinical and genetic heterogeneity. Next-generation sequencing techniques and predominantly whole exome sequencing have revolutionized the understanding of the genetic and molecular basis of genetic diseases, thereby also leading to a sharp increase in the discovery of new genes associated with primary immunodeficiencies. In this review, we discuss the current diagnostic yield of this generic diagnostic approach by evaluating the studies that have employed next-generation sequencing techniques in cohorts of patients with primary immunodeficiencies. The average diagnostic yield for primary immunodeficiencies is determined to be 29% (range 10–79%) and 38% specifically for whole-exome sequencing (range 15–70%). The significant variation between studies is mainly the result of differences in clinical characteristics of the studied cohorts but is also influenced by varying sequencing approaches and (in silico) gene panel selection. We further discuss other factors contributing to the relatively low yield, including the inherent limitations of whole-exome sequencing, challenges in the interpretation of novel candidate genetic variants, and promises of exploring the non-coding part of the genome. We propose strategies to improve the diagnostic yield leading the way towards expanded personalized treatment in PIDs.

scholarly journals Detection and validation of six pathogenic variants in Chinese inherited heart disease patients using clinical whole-exome sequencing

2021 ◽  
Author(s):  
Lichao Cao ◽  
Fei Ye ◽  
Shuqi Xie ◽  
Ying Ba ◽  
Ying Zeng ◽  
...  
Keyword(s):  
Heart Disease ◽  
Next Generation Sequencing ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Sanger Sequencing ◽  
Targeted Next Generation Sequencing ◽  
Pathogenic Variants ◽  
Whole Exome ◽  
Next Generation Sequencing Ngs ◽  
Generation Sequencing

The targeted next-generation sequencing (NGS) was employed in detecting the pathogenic mutations in inherited heart disease patients in the present study. Two main methods, the NGS and the classic Sanger sequencing, were used in this study. And, the whole-exome sequencing (WES) was specifically used in this study.

Whole genome sequencing (WGS), whole exome sequencing (WES) and clinical exome sequencing (CES) in patient care

2014 ◽  
Vol 38 (4) ◽  
Author(s):  
Hanns-Georg Klein ◽  
Peter Bauer ◽  
Tina Hambuch
Keyword(s):  
Patient Care ◽  
Exome Sequencing ◽  
Human Genetics ◽  
Massively Parallel Sequencing ◽  
Hla Typing ◽  
General Process ◽  
Flow Cells ◽  
Whole Exome ◽  
Next Generation Sequencing Ngs ◽  
Generation Sequencing

AbstractNext generation sequencing (NGS, also called Massively Parallel Sequencing) can be performed using a number of different platforms. The general process is very similar across them all: (1) extracted DNA is sheared into fragments (which, in targeted methods can be captured using probes); (2) these fragments are isolated physically on slides (usually called flow cells) or in emulsions and individually amplified, resulting in a library; and (3) the multiple individually amplified fragments are then simultaneously sequenced. After sequencing each fragment individually, the fragments must be re-assembled and the positions called using a series of bioinformatics algorithms. Excellent reviews are available that discuss the technical differences in detail. Recently, the value of NGS for diagnostics in patient care has been widely recognized and its applications include mutation detection in human genetics, molecular pathology and infectious agents as well as HLA typing, RNA sequencing and the detection of cell-free DNA. This paper focuses on applications of three different scales of NGS in human genetics diagnostics and evaluates its status based on our current understanding.

Εφαρμογή μεθοδολογιών αλληλούχησης επόμενης γενιάς (NGS) στη διάγνωση γενετικών ενδοκρινολογικών νοσημάτων

2020 ◽  
Author(s):  
Ελισάβετ-Βαρβάρα Τάτση
Keyword(s):  
Next Generation Sequencing ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Gene Panel ◽  
Next Generation ◽  
Whole Exome ◽  
Next Generation Sequencing Ngs ◽  
Generation Sequencing ◽  
Dependent Probe

Εισαγωγή: Μεγάλος αριθμός ενδοκρινολογικών νοσημάτων έχει γενετική αιτιολογία. Η εφαρμογή των μέχρι σήμερα ευρέως χρησιμοποιούμενων συμβατικών τεχνικών της Μοριακής Βιολογίας (π.χ. αλληλούχηση κατά Sanger) αδυνατεί να αποσαφηνίσει σε πολλές περιπτώσεις την γενετική διαταραχή. Την αδυναμία αυτή καλύπτει η αλληλούχηση επόμενης γενιάς (Next Generation Sequencing, NGS), η οποία επιτρέπει την παράλληλη και μαζική αλληλούχηση πολλών γονιδίων σε πολλούς ασθενείς ταυτόχρονα σε μια μόνο δοκιμασία. Χαρακτηριστικά παραδείγματα ενδοκρινολογικών νοσημάτων, των οποίων η αναγνώριση της μοριακής διαταραχής δεν είναι πάντα εφικτή με τις συμβατικές μεθόδους, αποτελούν ο Μονογονιδιακός Σακχαρώδης Διαβήτης (ΜΣΔ) MODY, ο Συγγενής Υπερινσουλινισμός (ΣΥ), η Πολλαπλή Υποφυσιακή Ανεπάρκεια (ΠΥΑ) και οι Διαταραχές Διαφοροποίησης του Φύλου (ΔΔΦ). Ασθενείς με ΜΣΔ MODY και ΣΥ παρουσιάζουν διαταραχές στην έκκριση της ινσουλίνης από τα β-κύτταρα των νησιδίων Langerhans του παγκρέατος. Συγκεκριμένα, ασθενείς με ΜΣΔ MODY παρουσιάζουν μειωμένη έκκριση ινσουλίνης και κατά συνέπεια υπεργλυκαιμία, ενώ ασθενείς με ΣΥ παρουσιάζουν αυξημένη έκκριση ινσουλίνης, δυσανάλογη προς τα κυκλοφορούντα επίπεδα γλυκόζης στο αίμα, και κατά συνέπεια υπογλυκαιμία. Ασθενείς με ΠΥΑ μπορεί να παρουσιάζουν ανατομικές ανωμαλίες της υπόφυσης και δυσμορφίες του προσώπου, καθώς και ανεπάρκεια τουλάχιστον δύο ορμονών της υπόφυσης, ενώ ασθενείς με ΔΔΦ παρουσιάζουν διαταραχές στον εμβρυολογικό καθορισμό και στην διαφοροποίηση του χρωμοσωμικού, γοναδικού και ανατομικού φύλου, με αποτέλεσμα την γέννηση νεογνών με αμφίβολα ή ασαφή έξω γεννητικά όργανα. Η μοριακή ταυτοποίηση της διαταραχής είναι θεμελιώδους σημασίας, όχι μόνο για την αναγνώριση των παθολογικών παραλλαγών των γονιδίων, τα οποία ευθύνονται για τα παραπάνω νοσήματα, αλλά και για τον συσχετισμό φαινότυπου-γονότυπου, για τη θεραπεία, την πρόγνωση και την αναγνώριση συνοδών χαρακτηριστικών της νόσου καθώς και για την παροχή γενετικής συμβουλευτικής στον ασθενή και στην οικογένεια του. Επιπλέον, προϋπόθεση για την ορθολογική αντιμετώπιση του νεογνού με ΔΔΦ αποτελεί η ταυτοποίηση της μοριακής βλάβης, η οποία μπορεί να καθορίσει την απόφαση για το φύλο του παιδιού, απόφαση με σημαντικές συνέπειες στην ψυχοκοινωνική προσαρμογή και τη μελλοντική ποιότητα της ζωής του. Σκοπός: Ο σκοπός της παρούσας διδακτορικής διατριβής ήταν η αποσαφήνιση της μοριακής διαταραχής, ασθενών με γενετικά ενδοκρινολογικά νοσήματα, στους οποίους οι μέχρι σήμερα χρησιμοποιούμενες τεχνικές μοριακής ανάλυσης απέτυχαν να εντοπίσουν την μοριακή βλάβη, με την εφαρμογή μεθοδολογιών αλληλούχησης επόμενης γενιάς (Next Generation Sequencing Targeted Gene Panel, NGS TGP και Whole Exome Sequencing, WES). Συγκεκριμένα, διερευνήθηκε η γενετική αιτία 50 ασθενών με MODY, 17 ασθενών με ΣΥ, 2 ασθενών με ΠΥΑ και 2 ασθενών με ΔΔΦ. Ασθενείς και Μέθοδοι: Πενήντα ασθενείς με MODY ελέγχθηκαν για την παρουσία παθολογικών παραλλαγών σε μια ομάδα 7 γονιδίων (GCK, HNF1A, HNF4A, HNF1B, INS, ABCC8 και KCNJ11), τα οποία είναι γνωστό ότι συνδέονται με τον ΜΣΔ MODY. Δεκαεπτά ασθενείς με ΣΥ ελέγχθηκαν για την παρουσία παθολογικών παραλλαγών στην παραπάνω ομάδα γονιδίων, πολλά από τα οποία έχουν συνδεθεί με το ΣΥ αλλά και σε ακόμα 5 γονίδια (GLUD1, HADH, INSR, SLC16A1, TRMT10A), τα οποία επίσης σχετίζονται με τον ΣΥ. Οι ασθενείς με MODY ή ΣΥ, στους οποίους δεν ανιχνεύθηκε παθολογική παραλλαγή με την μεθοδολογία του NGS, ελέγχθηκαν για απαλείψεις και διπλασιασμούς των γονιδίων GCK, HNF1A, HNF4A, HNF1B και ABCC8 με την μέθοδο του MLPA (Multiplex Ligation-dependent Probe Amplification). Επιπλέον, οι ασθενείς με ΣΥ στους οποίους δεν ανιχνεύθηκε παθολογική παραλλαγή με την μεθοδολογία του NGS, ελέγχθηκαν και για την παρουσία των παθολογικών ιντρονικών παραλλαγών c.1333-1013A>G του γονιδίου ABCC8 και c.636+471G>T του γονιδίου HADH με την αλληλούχηση κατά Sanger. Στα πλαίσια της παρούσας εργασίας, ακόμη, διερευνήθηκε η συχνότητα της παραλλαγής p.S385C του γονιδίου KCNJ11 στον Ελληνικό πληθυσμό. Με τη μέθοδο WES ελέγχθηκαν 2 ασθενείς με ΠΥΑ και 2 ασθενείς με ΔΔΦ, με σκοπό την ανίχνευση παθολογικών παραλλαγών που ευθύνονται για το φαινότυπό τους. Όλες οι παθολογικές παραλλαγές που ανιχνεύθηκαν με την μεθοδολογία του NGS, επιβεβαιώθηκαν με την αλληλούχηση κατά Sanger. Αποτελέσματα: Στο 28% (14/50) των ασθενών με MODY ανιχνεύθηκαν παθολογικές παραλλαγές των γονιδίων ABCC8 (8%, 4/50), GCK (8%, 4/50), HNF1A (6%, 3/50), HNF1B (4%, 2/50) και HNF4A (2%, 1/50). Στο 6% (3/50) βρέθηκαν αβέβαιης σημασίας παραλλαγές του γονιδίου ABCC8. Καμία παθολογική παραλλαγή δεν ανιχνεύθηκε στα γονίδια KCNJ11 και INS. Πέντε νέες παθολογικές παραλλαγές ανιχνεύθηκαν: η p.C371X του γονιδίου GCK, η p.N402Y του γονιδίου HNF1A, η p.E285K του γονιδίου HNF4A, η p.M1514T και η p.S1386F του γονιδίου ABCC8. Ακόμη, 2 ασθενείς με MODY έφεραν εκ νέου απάλειψη ολόκληρου του γονιδίου HNF1Β. Στο 23.5% (4/17) των ασθενών με ΣΥ ανιχνεύθηκαν παθολογικές παραλλαγές των γονιδίων ABCC8 (11.8%, 2/17), GCK (5.9%, 1/17) και HNF4A (5.9%, 1/17), ενώ στο 11.8% (2/17) των ασθενών με ΣΥ βρέθηκαν αβέβαιης σημασίας παραλλαγές των γονιδίων KCNJ11, INSR και HNF4A. Τρεις νέες παθολογικές παραλλαγές ανιχνεύθηκαν: η p.V71A του γονιδίου GCK, η p.R333P του γονιδίου HNF4A και η p.I445Sfs*5 του γονιδίου ABCC8. Η συχνότητα της παραλλαγής p.S385C του γονιδίου KCNJ11 στον Ελληνικό πληθυσμό βρέθηκε να είναι 1.35% (>1%), δηλαδή πολυμορφισμός. Με την εφαρμογή του WES στους 2 ασθενείς με ΠΥΑ ανιχνεύθηκαν παθολογικές παραλλαγές των γονιδίων HS6ST1, IL17RD, SOX9 (νέα παραλλαγή) και ΒΜΡ4, GNRH1, SRA1 αντίστοιχα, οι οποίες πιθανώς ευθύνονται για κάποια από τα κλινικά χαρακτηριστικά που παρουσιάζουν, ενώ στους 2 ασθενείς με ΔΔΦ ανιχνεύθηκαν παθολογικές παραλλαγές των γονιδίων TACR3, WNT7A και SAMD9 (εκ νέου παραλλαγή), PMM2, ACTN4 αντίστοιχα, οι οποίες πιθανώς ευθύνονται για τα κλινικά χαρακτηριστικά που παρουσιάζουν. Συμπεράσματα: Η εφαρμογή της μεθοδολογίας του NGS προσέφερε γενετική διάγνωση στο 28% των ασθενών με MODY και στο 23.5% των ασθενών με ΣΥ, επέτρεψε την ταυτοποίηση 5 νέων παθολογικών παραλλαγών σε ασθενείς με MODY και 3 σε ασθενείς με ΣΥ και αποκάλυψε ότι οι παθολογικές παραλλαγές του γονιδίου ABCC8 στους ασθενείς με MODY ήταν ισάριθμες με τις παθολογικές παραλλαγές του γονιδίου GCK των ασθενών με MODY. Επιπλέον, με την εφαρμογή του WES στους προηγουμένως αδιάγνωστους ασθενείς με ΠΥΑ και στους ασθενείς με ΔΔΦ ανιχνεύθηκαν αρκετές παραλλαγές, οι οποίες ευθύνονται για τα κλινικά χαρακτηριστικά τους. Συμπεραίνεται ότι η εφαρμογή της μεθοδολογίας του NGS προσφέρει γρήγορα αποτελέσματα, αυξάνει την διαγνωστική ακρίβεια και είναι πιο οικονομική σε σύγκριση με την αλληλούχηση κατά Sanger. Συνεπώς, η μεθοδολογία του NGS αποτελεί ένα χρήσιμο εργαλείο για τη διάγνωση γενετικών ενδοκρινολογικών νοσημάτων.

scholarly journals Pathogenic Mutations and Putative Phenotype-Affecting Variants in Polish Myofibrillar Myopathy Patients

2021 ◽  
Vol 10 (5) ◽  
pp. 914
Author(s):  
Anna Potulska-Chromik ◽  
Maria Jędrzejowska ◽  
Monika Gos ◽  
Edyta Rosiak ◽  
Biruta Kierdaszuk ◽  
...  
Keyword(s):  
Next Generation Sequencing ◽  
Exome Sequencing ◽  
Genetic Background ◽  
Degradation Products ◽  
Genetic Diagnosis ◽  
Phenotype Ontology ◽  
Myofibrillar Myopathy ◽  
Human Phenotype ◽  
Whole Exome ◽  
Generation Sequencing

Myofibrillar myopathies (MFM) are heterogeneous hereditary muscle diseases with characteristic myopathological features of Z-disk dissolution and aggregates of its degradation products. The onset and progression of the disease are variable, with an elusive genetic background, and around half of the cases lacking molecular diagnosis. Here, we attempted to establish possible genetic foundations of MFM by performing whole exome sequencing (WES) in eleven unrelated families of 13 patients clinically diagnosed as MFM spectrum. A filtering strategy aimed at identification of variants related to the disease was used and included integrative analysis of WES data and human phenotype ontology (HPO) terms, analysis of muscle-expressed genes, and analysis of the disease-associated interactome. Genetic diagnosis was possible in eight out of eleven cases. Putative causative mutations were found in the DES (two cases), CRYAB, TPM3, and SELENON (four cases) genes, the latter typically presenting with a rigid spine syndrome. Moreover, a variety of additional, possibly phenotype-affecting variants were found. These findings indicate a markedly heterogeneous genetic background of MFM and show the usefulness of next generation sequencing in the identification of disease-associated mutations. Finally, we discuss the emerging concept of variant load as the basis of phenotypic heterogeneity.

Whole-Exome Sequencing in Critically Ill Neonates and Infants: Diagnostic Yield and Predictability of Monogenic Diagnosis

Neonatology ◽  
2021 ◽  
pp. 1-8
Author(s):  
Tasja Scholz ◽  
Martin Ernst Blohm ◽  
Fanny Kortüm ◽  
Tatjana Bierhals ◽  
Davor Lessel ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Critically Ill ◽  
Whole Exome Sequencing ◽  
Diagnostic Yield ◽  
Human Phenotype ◽  
Whole Exome ◽  
Monogenic Diseases ◽  
Critically Ill Neonates ◽  
Neonates And Infants ◽  
The Impact

<b><i>Introduction:</i></b> Monogenic diseases play an important role in critically ill neonates and infants treated in the intensive care unit. This study aimed to determine the diagnostic yield of whole-exome sequencing (WES) for monogenic diseases and identify phenotypes more likely associated with a genetic etiology. <b><i>Methods:</i></b> From March 2017 to 2020, a comprehensive diagnostic workup including WES in a single academic center was performed in 61 unrelated, critically ill neonates and infants with an unknown underlying disease within the first year of life. We conducted 59 trio-WES, 1 duo-WES, and 1 single-WES analyses. Symptoms were classified according to the Human Phenotype Ontology. <b><i>Results:</i></b> The overall molecular genetic diagnostic rate within our cohort was 46% (28/61) and 50% (15/30) in the subgroup of preterm neonates. Identifying the genetic cause of disease facilitates individualized management in the majority of patients. A positive or negative predictive power of specific clinical features for a genetic diagnosis could not be observed. <b><i>Conclusion:</i></b> WES is a powerful noninvasive diagnostic tool in critically ill neonates and infants with a high diagnostic rate. We recommend initiating WES as early as possible due to the impact on management and family counseling. Recommendations regarding the clinical utility of WES in critically ill neonates and infants should not be based on the phenotype alone. Here, we present a clinical workflow for the application of WES for critically ill neonates and infants in an interdisciplinary setting.

scholarly journals One test for all: whole exome sequencing significantly improves the diagnostic yield in growth retarded patients referred for molecular testing for Silver–Russell syndrome

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Robert Meyer ◽  
Matthias Begemann ◽  
Christian Thomas Hübner ◽  
Daniela Dey ◽  
Alma Kuechler ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Diagnostic Yield ◽  
Uniparental Disomy ◽  
Molecular Testing ◽  
Main Body ◽  
Comprehensive Overview ◽  
Maternal Uniparental Disomy ◽  
Whole Exome ◽  
Silver Russell Syndrome

Abstract Background Silver-Russell syndrome (SRS) is an imprinting disorder which is characterised by severe primordial growth retardation, relative macrocephaly and a typical facial gestalt. The clinical heterogeneity of SRS is reflected by a broad spectrum of molecular changes with hypomethylation in 11p15 and maternal uniparental disomy of chromosome 7 (upd(7)mat) as the most frequent findings. Monogenetic causes are rare, but a clinical overlap with numerous other disorders has been reported. However, a comprehensive overview on the contribution of mutations in differential diagnostic genes to phenotypes reminiscent to SRS is missing due to the lack of appropriate tests. With the implementation of next generation sequencing (NGS) tools this limitation can now be circumvented. Main body We analysed 75 patients referred for molecular testing for SRS by a NGS-based multigene panel, whole exome sequencing (WES), and trio-based WES. In 21/75 patients a disease-causing variant could be identified among them variants in known SRS genes (IGF2, PLAG1, HMGA2). Several patients carried variants in genes which have not yet been considered as differential diagnoses of SRS. Conclusions WES approaches significantly increase the diagnostic yield in patients referred for SRS testing. Several of the identified monogenetic disorders have a major impact on clinical management and genetic counseling.

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